Continuous casting apparatus for casting corrugated cylinders



G. N. MENASOFF CONTINUOUS CASTING APPARATUS FOR CASTING Oct. 27, 1964 INVENTOR GEORGE N MENAsoFF United States Patent O 3,153,821 (N l lNlJUS CASTING APPARATUS FR CASTlNG CCDRRUGATED CYLNJERS George N. Menaso, Tarrytown, NX., assigner, by mesne assignments, to Anaconda Wire and Caole Company, a

corporation of Delaware Filed Get. 16, 1951, Ser. No. 145,964 3 Claims. (Cl. 22-57.2)

My invention relates to casting apparatus and particularly to apparatus for continuously casting an elongated cylindrical article of indefinite length.

lt has been known to obtain continuous lengths of cylindrical articles comprising materials such as aluminum, copper, and even steel by processes of extrusion. In extrusion processes the material to be extruded is heated to a temperature below its melting point and forced through dies by the application of very great pressure. Particularly it has been known to apply cable sheaths by the methods of extrusion, such sheaths being commonly formed of lead and lead alloys and of aluminum. A serious limitation or" extrusion processes, however, has resided in the cost and complexity of the apparatus due to the high pressures required. Anothe limitation has resided in the small size of the charges of materials, such as aluminum, that can be put into an extrusion chamber. This severely reduces the lengths of the extruded shapes that can be manufactured without discontinuities or weld marks and is a particular' hmdicap in the case of aluminum cable sheathing which is always subjected to a certain amount of llexing.

l have overcome these limitations by an apparatus that continuously casts material in cylindrical form. Due to the fact that high pressures are not required for casting, the apparatus of my invention is much less costly than a similar apparatus for extrusion and since material is fed into my casting apparatus in a molten state it can operate continuously without interruption for charging.

My apparatus for casting an elongated article cornprises a cylindrical die with an internal helical groove, means for introducing a liquid, solidiable material into the die and means for cooling the apparatus to form the material into a cylinder with an external projection matching the groove in the die. My apparatus also comprises means for cooling and means for rotating the die so as to eject the cylinder by the interaction or" the projection on the cylinder with the groove in the die. For casting a hollow cylinder my apparatus is comprised as above but with a cylindrical core.

Embodiments of my apparatus have helically grooved cores and smooth-walled dies, helically grooved dies and smooth-walled cores or helically grooved dies with matching helical threads on the cores. For continuously casting a cable sheath my apparatus has a core tube with a bore for receiving a cable. I have also provided my apparatus with means for supplying molten aluminum, a closed chamber for molten aluminum surrounding the core tube with the core tube extending above the level of molten aluminum in the chamber, means for maintaining a gas under pressure above the aluminum in the chamber, conduit means between the chamber and the storage supply, and pumping means for pumping molten aluminum through the conduit into the chamber. My apparatus also comprises means for swaging the sheath onto the cable.

A more thorough understanding of my invention will be obtained from a study ot the appended drawing.

ln the drawing:

FlGURE l is an elevational View, partly in section, of the apparatus of my invention.

FGURE 2 is an elevational iew, partly in section, of another embodiment of the apparatus or" my invention.

ICC

FlGURE 3 is a section in elevation of a detail of still another embodiment of my invention. v

Referring to FlGURE l, a casting machine indicated generally by the numeral 1li is connected to a supply tank ot molten aluminum 1l by means of a heat insulated pipe line 12 containing a valve 13. Although I have shown apparatus for casting aluminum it will be understood that l do not wish to be limited thereto and that my apparatus is suitable for continuously casting other metals and alloys such as copper and lead and is not limited to metals but can also be used for casting other materials that pass from a liquid to a solid state. The pipe 12 feeds into a tunnel-shaped chamber 14 at the top of the apparatus it? communicating with a cylindrical die 15 through an opening 16. A seal 17 preferably or" a lubricated, high-temperature type of which several are known prevents the escape of molten aluminum between the chamber 1li an dthe die 15. The die 1S' is threaded with an internal helical groove 1S which l have shown to extend the full length of the die. It wil be understood, however, that the groove 18 may start at some point below the top or" the die 15. Although I prefer the groove to have a single ight it will be understood that grooves ot two or more ilights may also be used within the scope ot my invention.

Molten aluminum from the supply l1 forms a pool 19 in the chamber lil which llows under the iniluence of gravity, augmented, where desired, by pressure inducing means hereinafter to be described, through the opening 16 of the conical chamber 14. |The die 15 is enclosed in a jacket 2l with passages 22 for a cooling fluid 23. l prefer to use water as the cooling fluid 23 for casting aluminum but l do not wish to be limited by this preference and it will be understood that other liquid and gaseous cooling media may also be used to cool the die 15. The lluid Z3 is introduced into the passages 22 through an aperture 24a from a source of such fluid, not shown, and leaves through another aperture Zeb to a cooling plant or sewer not shown. The die 1S has a bottom ange 25 and a lubricated seal 2o is interposed between this flange 25' and the jacket 21. A sprocket ring Z7 is locked onto the flange 25 by means of a set screw 28 and connected to a sproclcet wheel 29 by means of a chain belt The sprocket wheel Z9 is driven by means not shown to turn at any desired speed thereby causing the rotation of the die 15. As shown in the drawing the die l5' is rotated clockwise as seen from below). The aluminum t9 solidies in the die 1S to form a solid rod 3l having a helical projection 32 formed by the groove i3. The rotation of the die 15 continuously ejects the rod 31 by means or a screw action, in other words the reaction between the walls of the groove 18 and the helical projection 32. A pair of driven pinch rolls 33, 34 are mounted beneath the other elements of by apparatus to further urge and guide the cast rod.

An embodiment of my invention adapted to apply a cable sheath is shown in FGURE 2. In this figure a cable lli is passed continuously through a core tube 41 having a tapered bore d2. The word cable is used in this specitication to designate any elongated member which it is desired to cover with a sheath as shown herein and includes such commonly sheathed members as single insulated conductors, and multiple-conductor cable cores.

The core tube 4l has an external helical thread 43. Spaced from the core tube el and concentric thereto is a die d4 with a cooling jacket 45 having cooling passageways lo and cooling tluid ports 47, 48. Feeding into the annular space between the core tube 41 and the die 4d is a funnel-shaped chamber 49 holding a pool of molten aluminum Sil supplied through a conduit 51 connected through a pump S2 and a valve 53 to a supply tank 54. The chamber 49 is closed by a pressure cover 55 which is connected by means of pressure tubing 56 through a valve 57 to a source of pressurized gas', not shown. The core tube 41 has an upperportion 5S that extends through the cover S5, by means of a stuffing box 59. A sprocket ring 6) `is fastened to the top of the core tube extension 5S and a chain belt 61 connects'the sprocketv 60 to a sprocket wheel 62. The die 44 has a bottom flange 63 to which is fastened a sprocket ring 64 which is`linked by means of a chain belt 65 to a sprocket wheel 66. The sprocket wheels 62 and 66 are mounted on a common drive shaft 67 driven by a means not shown. The number of teeth in the sprocket wheel 62 equals the number of teeth in the wheel 66 and the teeth in the sprocket 60 are equal in number to the teeth in the sprocket 64 so that the die 44 Vturns at the same rpm. as the core tube having a contour uniformly spaced from and matching the helical configuration of the thread 43 on the core tube 41. Molten metal from the pool Sil fills the annular space between the die 44 and the core tube 41 and solidities to form a helically grooved sheath 69 spaced Y41. The die 44 has an internal helical groove 6t V from the cable 40 by the thickness of the walls of the core'tube 41. The die 44, however, extends below the core tube 41 which has a bottom edge 70. This lower portion 71 of the die 44 is tapered downwardly and has a swaging action on the sheath 69 compressing it inward- Y in FIGURE 3 is particularly advantageous for extruding hollow tubes. ln this apparatus an internal wall S13 of a die 81 is' smooth and free from any helical thread but I have provided a core 82 with an external helical thread 83. The die 81 remains stationary while the corel 82ViS outer walls, in the apparatus of FIGURE 1 the apparatus can be made to cast a hollow pipe instead of a solid bar. Additionally, if the threadl 43 is omitted from the core tube 41 of FTGURE 2, the extruded cable sheath will have the form of a pipe with anouter thread and smooth inner surface rather than the corrugations shown.-

I have invented a new and useful casting apparatus for which I desire an award of Letters Patent.

I claim:

1. Apparatus for casting a hollow cylinder comprising a cylindrical core, aV die concentric to said core deiining an annular space therewith, said die having an internal helical groove and said core having anrexternal helical projection matching said internal groove, means for introducing a liquid solidifiable material into the annular space between said core and said die, means for vcooling, said apparatus so as to solidify said material in 'the form of a helically grooved cylinder having suban internal helical groove matching said projection and defining an annular space therewith, means for introducing a liquid, solidiiable material into the annular space between said core tube and said die, means for cooling said die so as to solidify said material in the form of a helically grooved sheath having substantially uniform wall thickness, means for rotating said core tube and said die at a common speed relative to said sheath so as to eject said sheath, and means for swaging said sheath onto said cable.

3. Apparatus for continuously casting an aluminum cable sheath onto an electric cable comprising a storage supply for molten aluminum, a core tube having a bore for receiving a cable, a closed chamber for molten aluminum surrounding said core tube, said core tube extending above the level of molten aluminum in sald chamben means for maintaininga gas under pressure above the aluminum in said chamber, conduit Vmeans rotatedto eject a cast cylindery 84 by the interaction of the thread 83 and an internal matching groove S5 formed in the cylinder 84. Cooling of this castingis accomplished not only by a cooling jacket 86 around the die 81 and integral therewith but by internal cooling of the core 82. For this purpose the core 32 is hollowed outV to form a chamber 87 into which cooling water is introduced through a pipe 8S from a source not shown, and discharged through a pipe 89. IThe chamber S7 is sealed by means of a plug 91 through which the pipes S8 and 89 are sealed. The plug 91 is set in a stuing box 92 so that the pipes can remain stationary while the core 82 is rotated by means of a sprocket ring 93, chain 94 and sprocket wheel 96 driven by means not shown. To prevent the cooling water from solidifying the metal in the chamber 49 a close fitting bushing 97 is inserted at Y l the bottom of the pipe 89 and the pipes d8, S9 are in between said chamber and said storage supply, pumping means for pumping molten aluminum through said conduit means yinto said chamber, a die concentric to said core tube and defining an annular space therewith, said die having a helical internal groove and said core tube having a helical external projection matching said groove, said chamber communicating with said space whereby aluminum flows into and fills said space, means for cooling said die so as to solidify said aluminum in the form ofa helically grooved sheath having substantially uniform wall thickness, means for rotating said core tube and said die relative to said sheath so as to eject said sheath, and means for swaging said sheath onto said cable.

References Cited in the file of this patent UNITED STATES PATENTS 2,185,429 Burby Jan. 2, 1940 2,692,411 Brennan Oct. 26, 1954 2,801,441 Wadsworth Aug. 6, 1957 2,940,143 Daubersy et al. June 14, 1960 y FOREIGN PATENTS 618,536 Great Britain Feb. 23, 1947 

2. APPARATUS FOR CONTINUOSLY CASTING A CABLE SHEATH COMPRISING A CYLINDRICAL CORE TUBE HAVING A BORE FOR RECEIVING A CABLE, SAID CORE TUBE HAVING AN EXTERNAL HELICAL PROJECTION, A DIE CONCENTRIC TO SAID CORE TUBE HAVING AN INTERNAL HELICAL GROOVE MATCHING SAID PROJECTION AND DEFINING AN ANNULAR SPACE THEREWITH, MEANS FOR INTRODUCING A LIQUID, SOLIDIFIABLE MATERIAL INTO THE ANNULAR SPACE BETWEEN SAID CORE TUBE AND SAID DIE, MEANS FOR COOLING SAID DIE SO AS TO SOLIDIFY SAID MATERIAL IN THE FORM OF A HELICALLY GROOVED SHEATH HAVING SUBSTANTIALLY UNIFORM WALL THICKNESS, MEANS FOR ROTATING SAID CORE TUBE AND SAID DIE AT A COMMON SPEED RELATIVE TO SAID SHEATH SO AS TO EJECT SAID SHEATH, AND MEANS FOR SWAGING SAID SHEATH ONTO SAID CABLE. 